Skwerl, I joined yuku through www.yuku.com - my Australian surnames group had not been set up at the time so I am now rather confused why I would have that extension

I will have another go using the full extension name & report back

UPDATE: The result is the same as I previously reported

The info that was posted doesn't really make that clear - it says + .u OR .boardname and makes it appear you could use either one
------------------------------------------------

"Logging in:
Please make sure to always use your extension when signing in. You will not be able to sign in without your user extension.
Extension is username + .u or .boardname
Example: Chrisw.u or Chrisw.yukitagazette
The password to use here is your Yuku password."